This paper examines the succession planning strategies deployed by ideological factions at the level of the parliamentary Labour Party (PLP) in party leadership elections since 1963. The paper seeks to evaluate the short term tactics and long term strategies pursued by the ‘socialist left’ and the ‘social democratic right’ to enhance the prospect of their faction securing the lineage on the party leadership. The analysis will be undertaken by considering two key aspects of party leadership selection: first, ideological factions and the processes within which they determine, or fail to determine, who ‘their’ candidate should be; and, second, the importance of party leadership selection rules and the significance of the left’s commitment to shifting from a PLP ballot to an Electoral College based on their assumption that this would aid their succession planning. Incorporating analysis of each of the leadership contests since 1963, the paper suggests that the inability of the left to pass the threshold for participation in 2007 was a reflection of their tactical and strategic miscalculations in terms of succession planning dating back to 1980.